1. Technical Field
One or more embodiments of the present disclosure relate to a fuel cell system and a method of use.
2. Background Art
In a typical proton exchange membrane (PEM) based fuel cell system, an anode subsystem provides the necessary hydrogen fuel at the pressure, flow, and humidity to a fuel cell stack for necessary power generation.
During the normal operation of the fuel cell system, when a vehicle ignition key is turned on, the chemical reaction at an anode catalyst layer on an anode side of the fuel cell system involves splitting a hydrogen into an electron and proton. The protons permeate through the membrane to the cathode side. On the cathode side of the membrane, oxygen atoms react with the protons to produce water.
During a soak time period between a shutdown of normal operations and a restart of normal operations, some or all of the remaining unreacted hydrogen on the anode side migrates through the membrane and chemically reacts with the oxygen. Over time, depending upon the length of soak, hydrogen depletes in the anode side. Oxygen or air fills in the anode side to replace the lost hydrogen and increases an anode half cell potential. As a consequence of the increasing potential, carbon corrosion occurs in an anode catalyst layer. Carbon corrosion results in the loss of performance of the fuel cell and reduces the life of the fuel cell stack.
In addition, increasing the anode half cell potential destabilizes a ruthenium component of the anode catalyst layer. The ruthenium migrates to the cathode catalyst. The loss of ruthenium on the anode catalyst layer results in less efficient permeation of electrons and reduces the life of the fuel cell stack.
It is desirable to prevent oxygen and air from migrating to the anode side.